Final Report: Controls on Metals Partitioning in Contaminated Sediments

EPA Grant Number: R825513C012
Subproject: this is subproject number 012 , established and managed by the Center Director under grant R825513
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: HSRC (1989) - South and Southwest HSRC
Center Director: Reible, Danny D.
Title: Controls on Metals Partitioning in Contaminated Sediments
Investigators: Saunders, F. Michael , Jahnke, R. A. , Windom, H. L.
Institution: Georgia Institute of Technology
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1995 through January 1, 1998
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Hazardous Substance Research Centers , Land and Waste Management


The major objective of this research was to examine the applicability of the SEM:AVS ratio method to southeastern U.S. coastal sediments. More generally this work attempted to address a number of issues related to metal binding and bioavailability in contaminated sediments. These issues are delineated below.

  • The relationship between AVS and pore water trace metal concentrations using sediments that are typical of southeastern U.S. estuaries. This included the study of carbonate-rich sediments which have not been studied previously.

  • The influence of external factors on the overall pore water concentration - AVS relationship. Factors examined included temperature, overlying water oxygen concentration, periodic pore water oxidation, and periodic sediment mixing.

  • The characteristics of sedimentary phases other than AVS that are capable of binding pollutant metals and confounding SEM:AVS interpretation.

  • A quantitative assessment as to the effectiveness of a cap as an environmental remediation strategy. Similarly, capping was used as a means of assessing observable variations in sulfate reduction rates and mercury methylation rates.
  • Summary/Accomplishments (Outputs/Outcomes):

    Two types of microcosms were used to study the characteristics of southeastern U.S. sediments which control metal binding. A timed titration test reactor was designed to determine the overall binding capacity of sediment and the kinetic rates of reaction of the metal binding. The timed titration test reactor consisted of a 500 ml capacity Teflon jar containing 250 ml of sea water. The sea water used was well purged with a nitrogen and carbon dioxide mixture to ensure anaerobic conditions. To measure the addition of wet sediment sample, the reactor was placed on a balance. After the addition of the sample, the slurry was continuously purged and mixed (using a magnetic stirrer) during the timed test, a cadmium specific electrode and a reference electrode was placed within the reactor to measure the aqueous cadmium concentration. A cadmium spike (initially 0.15 ml of 1000 ppm) is added to the sediment slurry. Electrode readings were recorded with time to measure the change in the aqueous cadmium concentration. Additional cadmium spikes were added after the aqueous concentration approaches zero or reaches a level plateau (signifying saturation of binding sites). The timed titration test runs for approximately a week depending on the sediment being tested. The pH of the sediment sample is recorded daily, but is maintained, by the buffering of the purging gas, at 8.3.

    To allow testing on a larger variety of sediments by more rapid and multiple sample analysis, a second microcosm system for batch testing was designed. The batch test reactor consisted of a polypropylene bottle, containing 250 ml of sea water well purged with the nitrogen-carbon dioxide gas mixture. Prior to sediment addition, each reactor was spiked with varying concentrations of cadmium metal. The slurry was then repurged and measured for pH. Sodium hydroxide and HCl were added to adjust pH. After additional repurging, the sediment sample was added similar to the method in the timed titration. While under continuous purging, the sediment slurry was shaken on a mechanical shaker for approximately 48 hours. After completion of the 48 hours of shaking, an aliquot of the water was collected using a syringe and in-line filter. The aliquot was quickly acidified to avoid metal precipitation during storage. The aliquot was later analyzed for cadmium and iron by ICPMS. Studies to evaluate the relationship of AVS and other metals (Ni, Cu, Pb and Zn) using the "batch" method was also performed.

    The microcosm experiments provided a direct determination of the applicability of the SEM:AVS ratio for assessing metal toxicity in nearshore sediments in the southeastern U.S. A variety of potential problems were identified with the SEM:AVS ratio that make it difficult to apply in practice. Problems such as inconsistent handling, loss of sample integrity could make interpretation of SEM:AVS results difficult.

    This provides information on several concerns identified by the SAB including: the role of other binding phases in controlling pore water metal concentrations; the applicability of this approach to the sediment types found in the southeastern region; and an assessment of the response of the pore water metal - solid phase system to sediment disturbance that mimic the activities of benthic organisms.

    Journal Articles on this Report : 3 Displayed | Download in RIS Format

    Other subproject views: All 6 publications 4 publications in selected types All 3 journal articles
    Other center views: All 392 publications 154 publications in selected types All 106 journal articles
    Type Citation Sub Project Document Sources
    Journal Article Chen YC, Windom HL. Sediment manganese and biogenic silica as geochemical indicators in estuarine salt marshes of coastal Georgia, USA. Environmental Geochemistry and Health 1997;19(1):29-38. R825513C012 (Final)
    not available
    Journal Article King JK, Saunders FM, Lee RF, Jahnke RA. Coupling mercury methylation rates to sulfate reduction rates in marine sediments. Environmental Toxicology and Chemistry 1999;18(7):1362-1369. R825513C012 (Final)
    not available
    Journal Article Weisberg SB, Wilson HT, Heimbuch DG, Windom HL, Summers JK. Comparison of sediment metal: Aluminum relationships between the estuarine sediments from the eastern and gulf coasts of the United States. Environmental Monitoring and Assessment, 2000;61(3):373-385. R825513C012 (Final)
    not available

    Supplemental Keywords:

    SEM, AVS, and metal toxicity., RFA, Scientific Discipline, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Chemical Engineering, Contaminated Sediments, Environmental Chemistry, Fate & Transport, Analytical Chemistry, Hazardous Waste, Ecology and Ecosystems, Hazardous, Environmental Engineering, Mercury, environmental technology, sediment treatment, hazardous waste management, hazardous waste treatment, risk assessment, fate and transport, contaminated marine sediment, soil and groundwater remediation, biodegradation, contaminated sediment, kinetics, chemical contaminants, contaminated soil, bioremediation of soils, marine sediments, remediation, chemical kinetics, hydrology, biotransformation, currents, anaerobic biotransformation, extraction of metals, technology transfer, cadmium, heavy metals, aquifer fate and treatment, technical outreach

    Progress and Final Reports:

    Original Abstract
  • 1995
  • 1996

  • Main Center Abstract and Reports:

    R825513    HSRC (1989) - South and Southwest HSRC

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R825513C001 Sediment Resuspension and Contaminant Transport in an Estuary.
    R825513C002 Contaminant Transport Across Cohesive Sediment Interfaces.
    R825513C003 Mobilization and Fate of Inorganic Contaminant due to Resuspension of Cohesive Sediment.
    R825513C004 Source Identification, Transformation, and Transport Processes of N-, O- and S- Containing Organic Chemicals in Wetland and Upland Sediments.
    R825513C005 Mobility and Transport of Radium from Sediment and Waste Pits.
    R825513C006 Anaerobic Biodegradation of 2,4,6-Trinitrotoluene and Other Nitroaromatic Compounds by Clostridium Acetobutylicum.
    R825513C007 Investigation on the Fate and Biotransformation of Hexachlorobutadiene and Chlorobenzenes in a Sediment-Water Estuarine System
    R825513C008 An Investigation of Chemical Transport from Contaminated Sediments through Porous Containment Structures
    R825513C009 Evaluation of Placement and Effectiveness of Sediment Caps
    R825513C010 Coupled Biological and Physicochemical Bed-Sediment Processes
    R825513C011 Pollutant Fluxes to Aquatic Systems via Coupled Biological and Physicochemical Bed-Sediment Processes
    R825513C012 Controls on Metals Partitioning in Contaminated Sediments
    R825513C013 Phytoremediation of TNT Contaminated Soil and Groundwaters
    R825513C014 Sediment-Based Remediation of Hazardous Substances at a Contaminated Military Base
    R825513C015 Effect of Natural Dynamic Changes on Pollutant-Sediment Interaction
    R825513C016 Desorption of Nonpolar Organic Pollutants from Historically Contaminated Sediments and Dredged Materials
    R825513C017 Modeling Air Emissions of Organic Compounds from Contaminated Sediments and Dredged Materials title change in last year to "Long-term Release of Pollutants from Contaminated Sediment Dredged Material"
    R825513C018 Development of an Integrated Optic Interferometer for In-Situ Monitoring of Volatile Hydrocarbons
    R825513C019 Bioremediation of Contaminated Sediments and Dredged Material
    R825513C020 Bioremediation of Sediments Contaminated with Polyaromatic Hydrocarbons
    R825513C021 Role of Particles in Mobilizing Hazardous Chemicals in Urban Runoff
    R825513C022 Particle Transport and Deposit Morphology at the Sediment/Water Interface
    R825513C023 Uptake of Metal Ions from Aqueous Solutions by Sediments
    R825513C024 Bioavailability of Desorption Resistant Hydrocarbons in Sediment-Water Systems.
    R825513C025 Interactive Roles of Microbial and Spartina Populations in Mercury Methylation Processes in Bioremediation of Contaminated Sediments in Salt-Marsh Systems
    R825513C026 Evaluation of Physical-Chemical Methods for Rapid Assessment of the Bioavailability of Moderately Polar Compounds in Sediments
    R825513C027 Freshwater Bioturbators in Riverine Sediments as Enhancers of Contaminant Release
    R825513C028 Characterization of Laguna Madre Contaminated Sediments.
    R825513C029 The Role of Competitive Adsorption of Suspended Sediments in Determining Partitioning and Colloidal Stability.
    R825513C030 Remediation of TNT-Contaminated Soil by Cyanobacterial Mat.
    R825513C031 Experimental and Detailed Mathematical Modeling of Diffusion of Contaminants in Fluids
    R825513C033 Application of Biotechnology in Bioremediation of Contaminated Sediments
    R825513C034 Characterization of PAH's Degrading Bacteria in Coastal Sediments
    R825513C035 Dynamic Aspects of Metal Speciation in the Miami River Sediments in Relation to Particle Size Distribution of Chemical Heterogeneity